Method of and apparatus for cooling internal combustion engines



1933- M. B. BLEECKER METHOD OF AND APPARATUS FOR COOLING INTERNAL COMBUSTION ENGINES Filed July 8, 1950 5 Sheets-Sheet 1 AT-TORNEY NOV. 7, 1933. B BLEECKER 1,934,399

METHOD OF AND APPARATUS FOR COOLING INTERNAL-COMBUSTION ENGINES Filed July 8, 1930 5 Sheets-Sheet 2 FIGLSQ RNEY I M. B. BLEECKER 1,934,399

METHOD OF AND APPARATUS FOR COOLING INTERNAL COMBUSTION ENGINES Nov. 7, 1933.

' Filed July 8, 1930 5 Sheets-Sheet 3 INVENTOR M4117.

mvp 5545x42 ATTORNEY Nov. 7, 1933. M. B. BLEECKER METHOD OF AND APPARN'I'US FOR COOLING iNTERNAL COMBUSTION ENGINES V I 5 Sheets-Sheet 4 Filed July 8. 1930 FIG].

1933- M. B. BLEECKER METHOD OF AND APPARATUS FOR COOLING INTERNAL COMBUSTION ENGINES 5 Sheets-Sheet 5 Filed July 8, 1930 3 4 v 4 7 :J 4 7 1 a w m m 1 n H 1 r m J y Q h Ebb 3/ 4/ w W 2/ Z? 2 M ,V/// P-U M/// V 3 r J wi J- INVENTOR ATTORNEY Patented Nov. 7, 1933 UNITED STATES m-z'rnon or arm APPARATUS roa 000L- me mama cosmos-non enemas Maitland B. Bleecker, Hempstead, N. Y., assignor Oorporati to Wright Aeronautical ration of New York mamm- Application July 8, 193.. Serial No. 464,490 12 Claims. (Cl. 244-25) My invention relates to internal combustion engines and more particularly to cooling systems therefor. It is especially adapted for use in cooling airplane engines in airplanes of exceptionally large size, and in aircraft of the type known as helicopters and other special designs of aircraft.

Prior art The usual systems of cooling aeronautical motors are air cooling and liquid cooling. In air cooled motors it'has heretofore been customary to use a single propeller both for the purpose of propelling the aerial vehicle and also for forcing air past the cylinders for cooling the motor. In the case of airplanes, the propulsion of the vehicle through the air causes the motor to be drawn at a relatively high speed through the air and this movement, to a certain extent, aids the 2D cooling. So long as a direct'drive for the propeller is used and so long as the propeller isof relatively small size, such a system serves fairly well. However, the maximum'size of aircraft is increasing and it is becoming advisable to use 05 larger propellers. Inasmuch as the tip speed of the propellers is limited to a speed below the speedofsounditisnecessaryinsuchcasesto use a geared drive. Thereupon the crank shaft speed greatly exceeds the speed of the propeller and the air driven back by the propeller is insufllcient to cool the engine properly. Moreover, in large propellers, the section of the propeller adjacent to the hub is very inefficient in forcing back air and this hub ineiiiciency adds to the inadequacy of the cooling. For these reasons, except for my invention, the size of propellers appear to be limited.

In the case of aircraft in the nature of hellcopters, the lifting wings, which serve as propellers for lifting the aerial vehicle, revolve at an even smaller ratio to engine speed than in the case of the largest tractor airplanes at present known. Moreover, in the condition of hovering with such aircraft the motor is not dragged through the air at any forward speed so that the advantage of the passing air stream is totally eliminated in such cases.

Even in the case of direct drive propellers of ordinary size in conventional airplanes the flow of the air back from the propeller around the cylinders of an air cooled engine is notoriously inefficient. I have discovered that the flow continues in substantialLv straight lines past the maximum width of the cylinder and does not follow around the rear of the cylinder at all, and

I have found that the most important of the factors determining the cooling efllciency of the air blast are the speed of the air, the extent that the air follows the lines of the cylinder, and the amount of penetration between the fins.

Objects One of the objects of my invention is the emclent cooling of aeronautical motors even'when equipped with relatively large propellers driven bygeartrainsatspeedslessthanthespeedof the crank shaft of the motor.

A further object of my invention is the ellicient cooling of aeronautical motors irrespective of whether the motor itself is stationary or moving.

A further object of the invention is to provide means for directing and controlling the path of an adequate air blast on the motor irrespective of the'position, size and rate of rotation of the propelling propeller or propellers.

A further object of my invention is the construction of oil coolers so shaped and positioned that they serve the dual purposes of cooling oil and also of serving as deflectors for directing 80 the course of cooling air for the cylinders of the A further object of the invention is to provide means for cooling the motor of a helicopter.

Furtherobiectswillbeapparentfromareading of the subjoined specification and claims and from a consideration of the drawinss.

Drawings In order to explain the invention more clearly, several embodiments thereof are shown in said drawings. in which:

Fig. 1 is a view in perspective of a helicop illustrating my invention;

Fig. 2 is a ditic sectional view of a propeller drive and fan drive shown for the -purpwe of explaining the corresponding drives of the helicopter shown in Fig. 1; p

Pig. 3 is a sectional view through the motor shown in Fig. 1 illustrating in detail the associated parts of the drive for the propellers of the helicopter and the drive for the fan.

Fig. 4 is a sectional view of another part (more remote from the motor) of the driving mechanism for the propellers of the helicopter illustrated in Fig. 1;

Fig.5isaplanvlew ofthemotorshownin Fig. 1; v 110 General description As an illustration of my invention I have shown a helicopter equipped with rotatable wings, with a fuselage body and a motor. Each of the wings is provided with a tractor propeller driven through intermediate gearing by the motor. The wings and the motor secured thereto are caused to rotate in the air by the propellers but the fuselage or body of the aerial vehicle though suspended on the wings does not rotate therewith. Also driven from the motor by suitable gearing is a propeller fan by which an adequate blast of cooling air is drawn down and forced past the cylinders of the air cooled motor regardless of the rate of rotation of the lifting wings or of the translational speed of the helicopter as a whole. It is also to be noted that the tractor propellers on the wings are driven at less than crank shaft speed of the motor but that the fan is driven at crank shaft speed. I have provided deflectors between the cylinders of the air cooled motor by which the air driven by the fan is forced to follow the sides of the cylinders closely and therefore is able to cool the cylinders efliciently on all sides thereof. These deflectors are of novel contour so as to secure to the cylinders the greatest beneflt of the air stream created by the propeller fan and to secure uniform cooling of the cylinders on all sides thereof. Some of these deflectors are arranged also to serve as oil coolers.

Detailed description ,Referring in detail to the drawings in which like numerals have been used to designate the same or similar parts, I. have shown in Fig. 1 a helicopter formed with a fuselage 11 containing cockpits and seats for occupants. The helicopter is also equipped with a landing gear 12, which landing gear, together with the fuselage, is supported as at 14 upon a framework for substantially free rotation relative to the motor 13' and the wings. Secured to the motor by suitable frame work and adapted to revolve therewith are the four rotating wings 15, 16, 1'7 and 18. Each of these wings is equipped with a tractor propeller illustrated by the propellers 19, 20, 21'- and 22, respectively.

In Fig. 2 I have illustrated diagrammatically a form of drive for the propellers and cooling fan. It is not the preferred embodiment of my invention but it is thought that the invention will be more easily understood by reference thereto prior to a detailed description of the preferred form. As shown in Fig. 2 the crank shaft 23 of a motor 13 is provided with a gear 24 which meshes with spur gears 25 and 26 mounted on stub shafts 2'! and 28, respectively. The stub shafts are mounted in bearingsin a casing 29 made integral with the-cover 31 for the crank case 30 of the motor 13. The spur gears 25 and 26 are surrounded by a ring gear 37 which is provided with an interior gear 38 through which it is driven by said gears 25 and 26. The ring gear 3'! is also provided with an exterior bevel gear 39 by which it drives bevel gears 45, 46 and 47 and a fourth bevel gear (not shown). The bevel gears 45, 46 and 4'? and the fou th g a a e s cured to the horizontal drive shafts 41, 42 and 43 and a similar shaft, (not shown) respectively, and all mesh with bevel gear 39. The horizontal drive shafts are thus driven. The drive shaft 41 drives through intermediate gearing a propeller 19 and shaft 42 similarly drives a propeller 20. The other two drive shafts similarly drive two other like propellers (not shown). Inasmuch as all of these drives are alike, they are all adequately illustrated by the drive of the propeller shaft 51 shown at the right of Fig. 2. The horizontal shaft 43 is provided at its outer end with a bevel gear 48 meshing with another bevel gear 49 within the gear casing 50. The bevel gear 49 is secured to a propeller shaft 51 on which is mounted a propeller corresponding to propeller 21.

The propeller fan drive is also illustrated. Secured to the stub shaft 27 is another spur gear 52 and secured to the stub shaft 28 is another spur gear 53. The gears 52 and 53 mesh with an external gear 54 formed on the sleeve 55. Also secured to the sleeve 55 is a propeller fan 56 by which cooling air is forced over the cylinders of the motor.

As stated, the embodiment illustrated in Fig. 2 does not comprise the preferred forms of propeller and fan drives constructed according to my invention. The preferred forms are shown in Figs. 3 and 4. Therein, the crank shaft 23 extends forward out of the main crank case 30, and the reduction gear unit is positioned in the nose of the engine and surrounds this extension. Supported by the main part of the crank case 30 is a fixed machined part 31* which is secured to said crank case 30. The part 31 has formed integral therewth an annular flange 61 which surrounds the crank shaft 23. Supported upon the flange 61 is a fixed steel ring 62 also annular in shape and-also surrounding the crank shaft 23. The ring 62 and part 31 are both provided with internal splines. They are pressed on to an externally splined sleeve 63 and threaded rings or nuts 63 and 63 screwed upon the ends of the sleeve 63 hold said parts in rigid assembly. Supported upon the ring 62 is another stationary annular casting 64 which supports a fixed ring 65 formed with internal gear teeth 66. The gear teeth 66 mesh with a fixed or sun gear 67 which is mounted on the ball bearings '70, to allow the rotation of the crank shaft therein. Supported upon the ring 65 is the gear case 68 which is secured thereto by studs such as the stud 69.

Surrounding the crank shaft 23* throughout the lower part of the gear case 68 is a bevel gear 24 which may be called the drive gear. The bevel gear 24 is splined to the crank shaft 23 and adapted to rotate therewith. The teeth of the bevel gear 24 mesh with the teeth of several planetary gears or bevel pinons each of which is similar to the planetary gear 71 and each of for rotation about stub shafts such as the stub shafts '13 and 73 The stub shafts 73 and '73 are connected with the stub shafts provided for the other planetary gears by means of a flexible ring formed of links '74 secured to the stub shafts by pins 75. Each planetary gear also meshes with the fixed or sun gear 67 sothat the planetary gears and the connecting links rotate about the crank shaft at one-half of crank shaft speed. Each planetary gear has formed integral therewith a cylindrical extension such as 76 for driving the cage presently to be described.

A two piece pinion cage 77 has an upper secmounted a propeller 21'.

tion '77 andv a lower section '7'7 joined by bolts such as '78. The cage '77 is provided with openings extending substantially vertically, through which the planetary gears extend tomesh with the drive gear 24 and with the flxed or sungear 6'7. It is also provided with openings extending substantially radially through which the extension '76 and the other cylindrical extensions corresponding thereto extend forming a driving connection between the bevel pinions and the cage. The cage '77 thus rotates with the planetary gears at one half engine speed, and has formed thereon an internal gear 79 which meshes with external gear teeth formed on the ring gear 80. The ring gear 80 has also bevel teeth 81 which mesh with four bevel gears. Each of these four gears drives one of the propellers but inasmuch as all four are alike I have only shown the gear 4'7 and its cooperating elements as an illustration of all of the propeller drives; The gear 47 is carried on a shaft 43 which is mounted in ball bearings 82 and 83 carried by the upper part of the gear casing 68. The gear ratio between ring gear 80' and bevel gea14'7 is such that the gear 47* is driven at less than crank shaft speed but at a greater speed than one half of the speed of the crank shaft 23. By the mounting of the" parts and the toothed connections at 66 and '79, a floating clutchis provided which prevents any external. loads reaching the reduction gearing and vice versa. Incidentally, thereby, provision is made for expansion of the metals due to heat, as well as for manufacturing inaccuracies and for ease of assembly.

The more remote part of the propeller drive is shown more clearly Figs. 1 and 4. The shaft 43* extends outward to a gear case 50 where it is supported by ball bearings 84 and 85. The gear case 50 is itself supported by a series of braces including the rods 86 and 8'7. Secured to the shaft 43 within the gear case 50 is a bevel gear 48' which meshes with a cooperating bevel gear 49" secured to a shaft 51' on which is A bearing case 88 is secured to the gear case 50 and carries a pair of bearings 89 and 91 for supporting the-shaft 51. It is to be understood that the propellers-19', 20* and 22- are driven by exactly similar elements from the ring gear 80.

I provide an auxiliary fan for causing air to circulate over the motor in order that it may be efllciently cooled even though the blades 15, 16, 1'7 and 18, which serve as a propeller. for lifting my improved type of aerial vehicle into the air, are rotating at a speed considerably less than the crank shaft speed of the engine and even though the blades of this lifting propeller are so large and of such shape that the portions thereof adjacent to the engine produce relatively little downward drive of air past the engine. Referring again to Fig. 3, it may be seen that the annular casting 6.4 is provided with an eccentric annular flange 94 adapted to receive a roller bearing ring 95. On the bearing ring 95 is mounted a pinion 96 having an upper set of gear teeth 9'7 and a lower set of gear teeth 98. A ring 95* threaded on to the flange 94 and a ring 95 threaded on to the pinion 96 maintain the bearing ring 95 in position. A plate 99 secured to the casting 64 seals against leakage of oil. The upper series of gear teeth 97 mesh with an annular gear 100 formed on a sleeve 101 splined to the crank shaft 23 and mounted to rotate therewith. Inasmuch as the casting 64 is maintained substantially stationary due to its connection ,jacent pair of the cylinders of the motor.

with the crank case 30 the gear teeth 100 cause the rotation of the pinion 96 about the bearing ring 95. The lower series of gear teeth 98 mesh with a gear 102 secured to the fan 56*. The fan 56 and gear 102 are mounted on ball bearings 103 and 103 and are thus free for rotation.

The gear ratios insure that the fan 56 is rotated at engine speed. If desired, 'however, the gear ratios may be varied so as to drive the fan at a greater speed .or at a slower speed than that of the engine.

I also provide additional means for aiding the eflicient cooling of thecylinders of the motor.

cured to the tube 107 for the exhaust valve fol-.

lower or push rod. The deflector 106 is formed somewhat in wedge shape so as to divide the current of air which passes it and to force said current of air to approach and follow the sides of the cylinders 104 and 105. The rearward end of the deflector 106 is extended as at 108 and 109 around the rear part of the cylinders, thus causing the ar to follow the contour of the rear part of the cylinders and cool that part. Moreover, as seen in horizontal section in Fig. '7, the deflector is shaped so as to follow the irregular contour of the cylinders according to their outline as they extend outward from the crank case. Each of the other deflectors is sim'larly constructed. A light strip 111 formed as a hoop surrounds the motor and to this strip each one of the deflectors corresponding to the deflector 106 is secured. The strip 111 thus cooperates with the push rod tubes to maintain the baflles in their proper positions;

It is to be especially noted that the baflies 106 are not symmetrical in outline as viewed in Fig. 6. The stream formed by the propeller 56 does not follow a path straight back but is a rotating or whirling column. Moreover, the engine 13 rotates the wings 15, 16, 17 and 18 and with the wings turns the motor itself in a direction opposite to the rotation of this stream or blast of a r, thus increasing the relative rotation between the stream of air and the cylinders of the motor. By the shape of my improved deflectors this stream of air is thus evenly distr'buted among the various cylinders and around the sides thereof. The deflectors are so shaped and formed that the least possible space is allowed between the outer ends of the fins and each deflector. Thus substantially all of the air is forced to pass between the fins of the cylinders. The stream of air passed through these small spaces, speeds up because of a Venturi tube effect and thus effects the most efficient cool ng of the cylinders. I also provide deflectors between the rocker boxes at the head of the cylinder so as to catch the air that is spilled over the edge of the motor and to carry it around through the pompadour lips of the cylinder head itself. As shown in Figs. 5 and '7 the deflectors 112 are shaped to correspond to the shape of the openings between the valve rocker boxes at the head of the cylinder allowing only a narrow passage-for the stream of air flowng past the cylinder. Moreover, I utilize these outer deflectors for the additional purpose of cooling the oil used in the motor.- Each of these deflectors 112 is an oil radiator provided as is customary in oil coolers with many small air passages through which the cooling air flows, and also with small separate passages through which the oil to be cooled flows The air passages are preferably formed obliquely so that they are parallel to the normal oblique flow of the air discussed above in reference to the deflectors 106.

A pipe 113 leads oil from the outlet of one of the cylinders to the oil pump from which it is distributed to the motor for the purpose of lubricating it. A second pipe 114 supplies the used oil to the inlet of another one of the oil coolers 112. The outlets from all of the oil coolers except the first mentioned, are connected by pipes 115 to the inlets of the adjacent coolers so that a circuit is provided for all of the oil through all of the oil coolers. A hoop 116 similar to, the hoop 111 (but heavier than said hoop) serves as a support for the oil coolers 112, being fastened thereto by clamps 116 (omitted for the sake of clearness in Fig. 5).

In Fig. 8 I have shown a sectional view of a reduction gear mechanism including drives for the propellers and for the fan corresponding to the showing of Fig. 3, but illustrating a slightly modified form of device embodying my invention. Therein I have shown a crank shaft 123 extending upward through a gear case 168 and I have also shown a drive gear 124, planetary gears 171, a sun gear 167, and a pinion cage 177 all similar to corresponding parts shown in Fig. 3. The cage 177 has formed thereon an internal gear 179 which meshes with external gear teeth formed on the ring gear 180. The latter meshes with four similarbevel gears, two of which are shown and designated 147 and 147. Each of these bevel gears is carried on a horizontal shaft similar to the shafts 143 and 143 and each through said shaft drives a propeller for one of the wings of a helicopter in a manner similar to that shown and described with reference to the embodiment- Operation In the operation of an aerial vehicle constructed according to the embodiment of my invention shown in Fig. 2 the engine 13 drives the crank shaft 23 and through the gears 24, 25, 26 and 37 drives the bevel gears 45, 46, 47 and a fourth bevel gear corresponding thereto and through these bevel gears drives the horizontal shafts 41, 42, 43 and a fourth similar shaft, not shown. Each of these shafts drives a propeller shaft similar to the propeller shaft 51 through a chain of gears corresponding to the bevel gears 48 and 49.

" Each of the propeller shafts carries a propeller such as the propellers 19 and 20 and by the rotation thereof causes the rotation of the wings 15, 16, 17 and 18. The wings 15, 16, 17 and 18 thus form in effect a lifting propeller of very large size rotating at relatively low speed compared to the speed of rotation of the crank shaft 23. The rotation of the wings 15, 16, 17 and 18 lifts the aerial vehicle into the air and by controlled tilting of the wings horizontal flight is also possible.

The gears 25 and 26 being secured to the shafts 27 and 28 cause by their rotation the simultaneous rotation of the gears 52 and 53 and through those gears the sleeve 55 and the fan 56. The fan 56 causes a stream of air to flow backward over the cylinders of the motor 13. Between each pair of these cylinders the deflectors corresponding to the deflector 106 control the path of the stream of air so that it flows all around the outside of each of the cylinders in a passage approximately equal to the depth of the fins and thus a highly etficient cooling of the cylinders is obtained. The outer deflectors also serve as oil radiators for cooling the lubricating oil.

In the form of device shown in Figs. 3 and 4 the crank shaft 23 causes the rotation of the bevel drive gear 24 which in turn causes the rotation of the planetary gears or bevel pinions both about their stub shafts. The fact that these planetary gears are also meshed with the stationary sun gear 67 causes the simultaneous rotation of the planetary gears about the crank shaft 23. The rotation about the crank shaft 23 is at one half the speed of the crank shaft 23 and causes the rotation of the cage 77 and the ring gear 80 at the same' speed. The ring gear 80 causes the rotation of the bevel gear 47 and the shaft 43 at a speed less than crank shaft speed but greater than the speed of rotation of the ring gear 80. The shaft 43 through the bevel gears 48 and 49 drives the shaft 51 and the propeller 21*. The other three propellers 19*, 20 and 22 are driven in a similar manner from the ring gear 80 and thus cause the rotation of the wings 15, 16, 17 and 18 or large lifting propeller and the consequent lifting of the aerial vehicle. Forward motion is obtained in a manner similar to that described in the modification shown in Figs. 1 and 2.

The annular gear drives the pinion 96 and through it the gear 102 and the fan 56. The fan 56 is driven at engine speed and in a manner similar to that described in connection with the modification shown in Fig. 2 causes a stream of air to flow past the cylinders of the motor for cooling it. The device shown in Fig. 8 operates similarly to that shown in Figs. 3 and 4. The propeller fan, however, is driven from the reduction gearing at substantially one half engine speed instead of being independently driven from the crank shaft at engine speed.

It is to be understood that the above described embodiments of my invention are for the purpose of illustration only and various changes may be made therein without departing from the spirit and scope of the invention.

I claim as my invention: I

1. In aircraft, a motor, cylinders for said motor, a valve operating mechanism for each cylinder, a casing for each said valve operating mechanism, means for causing a stream of air to flow past the cylinders of said motor, and deflectors inserted between adjacent cylinders for directing and controlling the course of said stream of air around said cylinders, each of said deflectors being supported upon one of said casings.

2. In aircraft; a motor; cylinders for said motor; a valve operating mechanism including a push rod for each cylinder; casings for said push rods; means for causing a stream of air to flow past the cylinders of said motor; deflectors inserted between adjacent cylinders for directing and controlling the course of said stream of air around said cylinders, each of said deflec- 'tors being supported upon one of said casings;

and a circular strip secured to all of said deflectors.

3. In aircraft, a motor, cylinders for said motor, means cooperating with said motor for causing its rotation, means for causing a stream of air to flow past the cylinders of said motor, and deflectors inserted between adjacent cylinders for directing and controlling the course of said stream of air around said cylinders, said deflectors being of a substantially wedge shape with the point of the wedge inclined toward the direction of rotation of the motor.

4. In aircraft, a motor, cylinders for said motor, means for causing a rotating stream of air to flow past the cylinders, and deflectors inserted between adjacent cylinders for directing and controlling the course of said stream of air around said cylinders, said deflectors being of substantially wedge shape and having the point thereof inclined toward the direction of rotation of the stream of air.

5. A drive forluse in connection with aircraft comprising a drive shaft, a stationary sleeve surrounding said shaft, a stationary member supported upon said sleeve, a pinion carried by said stationary member, a-gear splined to said drive shaft and driven thereby and meshed with said pinion for driving said pinion, and a gear surrounding said sleeve, meshed with said pinion and driven thereby.

8. In an aeronautical motor, a plurality of cylinders, means for causing\ a stream of air to flow over said cylinders, a deflector positioned adjacent to one of the cylinders for causing a part of the stream of airto follow a narrow path adjacent to said cylinder, and means for causing lubricating oil to be passed through said: deflector for cooling said lubricating oil.

7. An aeronautical motor comprisinga cylinder, a pair of rocker box housings secured to the head of said cylinder, means for causing air to flow between said housings, and a deflector positioned between said housings for controlling said stream of air and causing it to flow in a path closely adjacent to said housings.

8. The combination, in aircraft, of a radial cylinder engine having divergent rocker boxes at the outer cylinder ends, a circular member within the embrace of which the engine is held, and air deflectors interposed between the outer cylinder ends and said circular member to occupy the space between said divergent rocker boxes.

9. The combination, in aircraft, of a radial cylinder engine having spaced rocker boxes at the outer cylinder ends, .air deflectors arranged to occupy the space between said rocker boxes, and a motor encircling member to which said air deflectors are attached.

10. The combination, in aircraft, of a radial cylinder engine having spaced rocker boxes at the outer cylinder ends, means for directing a cooling blast of air toward said engine cylinders, deflectors inserted between adjacent engine cylinders for directing said blast of air toward the rear cylinder walls, deflectors inserted between the spaced rocker boxes for directing said blast of air closely adjacent the rocker box walls, and a support means for said last mentioned deflectors arranged to encircle the engine.

11. In means for cooling aircraft engines of the radial cylinder type. a relatively large slow speed propeller driven thru a speed reducing mechanism by said engine, and an auxiliary proj cated between said first mentioned propeller and 

